Fix get_icon

Property reply functions are now notified if there was an error with the
property instead of silent failure. Also issues in `get_item` were
resolved.

include/swaybar/tray/dbus.h

@@ -5,6 +5,13 @@
 #include <dbus/dbus.h>
 extern DBusConnection *conn;
 
+enum property_status {
+	PROP_EXISTS, /* Will give iter */
+	PROP_ERROR, /* Will not give iter */
+	PROP_BAD_DATA, /* Will not give iter */
+	PROP_WRONG_SIG, /* Will give iter, please be careful */
+};
+
 /**
  * Checks the signature of the given iter against `sig`. Prefer to
  * `dbus_message_iter_get_signature` as this one frees the intermediate string.
@@ -15,8 +22,9 @@ bool dbus_message_iter_check_signature(DBusMessageIter *iter, const char *sig);
  * Fetches the property and calls `callback` with a message iter pointing it.
  * Performs error handling and signature checking.
  *
- * Returns: true if message is successfully sent (will not necessarily arrive)
+ * Returns: true if message is successfully sent and false otherwise. If there
- * and false otherwise
+ * is an error getting a property, `callback` will still be run, but with
+ * `status` set to the error.
  *
  * NOTE: `expected_signature` must remain valid until the message reply is
  * received, please only use 'static signatures.
@@ -26,7 +34,7 @@ bool dbus_get_prop_async(const char *destination,
 		const char *iface,
 		const char *prop,
 		const char *expected_signature,
-		void(*callback)(DBusMessageIter *iter, void *data),
+		void(*callback)(DBusMessageIter *iter, void *data, enum property_status status),
 		void *data);
 /**
  * Should be called in main loop to dispatch events

swaybar/tray/dbus.c

@@ -138,7 +138,7 @@ static void dispatch_status(DBusConnection *connection, DBusDispatchStatus new_s
 
 struct async_prop_data {
 	char const *sig;
-	void(*callback)(DBusMessageIter *, void *);
+	void(*callback)(DBusMessageIter *, void *, enum property_status);
 	void *usr_data;
 };
 
@@ -160,6 +160,7 @@ static void get_prop_callback(DBusPendingCall *pending, void *_data) {
 				DBUS_TYPE_INVALID);
 
 		sway_log(L_INFO, "Failure to get property: %s", msg);
+		data->callback(NULL, data->usr_data, PROP_ERROR);
 		goto bail;
 	}
 
@@ -169,16 +170,18 @@ static void get_prop_callback(DBusPendingCall *pending, void *_data) {
 	dbus_message_iter_init(reply, &iter);
 	if (dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_VARIANT) {
 		sway_log(L_ERROR, "Property relpy type incorrect");
+		data->callback(NULL, data->usr_data, PROP_BAD_DATA);
 		goto bail;
 	}
 	dbus_message_iter_recurse(&iter, &variant);
 
 	if (!dbus_message_iter_check_signature(&variant, data->sig)) {
 		sway_log(L_INFO, "Property returned has incorrect signatue.");
+		data->callback(&variant, data->usr_data, PROP_WRONG_SIG);
 		goto bail;
 	}
 
-	data->callback(&variant, data->usr_data);
+	data->callback(&variant, data->usr_data, PROP_EXISTS);
 
 bail:
 	if (reply) {
@@ -199,7 +202,8 @@ bool dbus_message_iter_check_signature(DBusMessageIter *iter, const char *sig) {
 bool dbus_get_prop_async(const char *destination,
 		const char *path, const char *iface,
 		const char *prop, const char *expected_signature,
-		void(*callback)(DBusMessageIter *, void *), void *usr_data) {
+		void(*callback)(DBusMessageIter *, void *, enum property_status),
+		void *usr_data) {
 	struct async_prop_data *data = malloc(sizeof(struct async_prop_data));
 	if (!data) {
 		return false;

swaybar/tray/sni.c

@@ -41,11 +41,15 @@ void sni_icon_ref_free(struct sni_icon_ref *sni_ref) {
 }
 
 /* Gets the pixmap of an icon */
-static void reply_icon(DBusMessageIter *iter /* a(iiay) */, void *_data) {
+static void reply_icon(DBusMessageIter *iter /* a(iiay) */, void *_data, enum property_status status) {
+	if (status != PROP_EXISTS) {
+		return;
+	}
 	struct StatusNotifierItem *item = _data;
 
 	DBusMessageIter d_struct; /* (iiay) */
-	DBusMessageIter icon; /* ay */
+	DBusMessageIter struct_items;
+	DBusMessageIter icon;
 
 	if (dbus_message_iter_get_element_count(iter) == 0) {
 		// Can't recurse if there are no items
@@ -54,16 +58,17 @@ static void reply_icon(DBusMessageIter *iter /* a(iiay) */, void *_data) {
 	}
 
 	dbus_message_iter_recurse(iter, &d_struct);
+	dbus_message_iter_recurse(&d_struct, &struct_items);
 
 	int width;
-	dbus_message_iter_get_basic(&d_struct, &width);
+	dbus_message_iter_get_basic(&struct_items, &width);
-	dbus_message_iter_next(&d_struct);
+	dbus_message_iter_next(&struct_items);
 
 	int height;
-	dbus_message_iter_get_basic(&d_struct, &height);
+	dbus_message_iter_get_basic(&struct_items, &height);
-	dbus_message_iter_next(&d_struct);
+	dbus_message_iter_next(&struct_items);
 
-	int len = dbus_message_iter_get_element_count(&d_struct);
+	int len = dbus_message_iter_get_element_count(&struct_items);
 
 	if (!len) {
 		sway_log(L_ERROR, "No icon data");
@@ -76,7 +81,7 @@ static void reply_icon(DBusMessageIter *iter /* a(iiay) */, void *_data) {
 		return;
 	}
 
-	dbus_message_iter_recurse(&d_struct, &icon);
+	dbus_message_iter_recurse(&struct_items, &icon);
 
 	int stride = cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, width);
 	// FIXME support a variable stride
@@ -131,9 +136,16 @@ static void reply_icon(DBusMessageIter *iter /* a(iiay) */, void *_data) {
 }
 
 /* Get an icon by its name */
-static void reply_icon_name(DBusMessageIter *iter, void *_data) {
+static void reply_icon_name(DBusMessageIter *iter, void *_data, enum property_status status) {
 	struct StatusNotifierItem *item = _data;
 
+	if (status != PROP_EXISTS) {
+		dbus_get_prop_async(item->name, item->object_path,
+			(item->kde_special_snowflake ? KDE_IFACE : FD_IFACE),
+			"IconPixmap", "a(iiay)", reply_icon, item);
+		return;
+	}
+
 	char *icon_name;
 	dbus_message_iter_get_basic(iter, &icon_name);
 

swaybar/tray/tray.c

@@ -38,7 +38,10 @@ static void register_host(char *name) {
 	dbus_message_unref(message);
 }
 
-static void get_items_reply(DBusMessageIter *iter, void *_data) {
+static void get_items_reply(DBusMessageIter *iter, void *_data, enum property_status status) {
+	if (status != PROP_EXISTS) {
+		return;
+	}
 	DBusMessageIter array;
 
 	// O(n) function, could be faster dynamically reading values
@@ -60,7 +63,10 @@ static void get_items_reply(DBusMessageIter *iter, void *_data) {
 		}
 	}
 }
-static void get_obj_items_reply(DBusMessageIter *iter, void *_data) {
+static void get_obj_items_reply(DBusMessageIter *iter, void *_data, enum property_status status) {
+	if (status != PROP_EXISTS) {
+		return;
+	}
 	DBusMessageIter array;
 	DBusMessageIter dstruct;